according to BindComposer.java method "initValidationMessages" method, I can use init annotation with validationMessages

validationMessages="@id('vmsgs') @init('MyValidationMessages')"

also refer to attached sample code

but it cause exception
org.zkoss.zk.ui.UiException: Property 'validationMessages' not found on type org.zkoss.zul.Window at file:/C:/Users/ace/workspace/zk/zktest2/WebContent/validation.zul, line:16
at org.zkoss.bind.impl.MiscUtil.mergeExceptionInfo(MiscUtil.java:175)
at org.zkoss.bind.impl.BindEvaluatorXImpl.setValue(BindEvaluatorXImpl.java:61)
at org.zkoss.bind.impl.InitPropertyBindingImpl.load(InitPropertyBindingImpl.java:78)
at org.zkoss.bind.impl.PropertyBindingHandler.doLoadBinding(PropertyBindingHandler.java:171)
at org.zkoss.bind.impl.PropertyBindingHandler.doInit(PropertyBindingHandler.java:381)
at org.zkoss.bind.impl.BinderImpl.loadComponentProperties0(BinderImpl.java:2088)
at org.zkoss.bind.impl.BinderImpl.loadComponent0(BinderImpl.java:2067)
at org.zkoss.bind.impl.BinderImpl.loadComponent(BinderImpl.java:2058)
at org.zkoss.bind.BindComposer$BinderKeeper$Loader.load(BindComposer.java:490)
at org.zkoss.bind.BindComposer$BinderKeeper.loadComponentForAllBinders(BindComposer.java:469)
at org.zkoss.bind.BindComposer.doAfterCompose(BindComposer.java:178)
at org.zkoss.zk.ui.impl.UiEngineImpl.doAfterCompose(UiEngineImpl.java:537)
at org.zkoss.zk.ui.impl.UiEngineImpl.execCreateChild0(UiEngineImpl.java:832)
at org.zkoss.zk.ui.impl.UiEngineImpl.execCreateChild(UiEngineImpl.java:778)
at org.zkoss.zk.ui.impl.UiEngineImpl.execCreate0(UiEngineImpl.java:687)
at org.zkoss.zk.ui.impl.UiEngineImpl.execCreateChild(UiEngineImpl.java:749)
at org.zkoss.zk.ui.impl.UiEngineImpl.execCreate0(UiEngineImpl.java:709)
at org.zkoss.zk.ui.impl.UiEngineImpl.execCreate(UiEngineImpl.java:651)
at org.zkoss.zk.ui.impl.UiEngineImpl.execNewPage0(UiEngineImpl.java:401)
at org.zkoss.zk.ui.impl.UiEngineImpl.execNewPage(UiEngineImpl.java:316)
at org.zkoss.zk.ui.http.DHtmlLayoutServlet.process(DHtmlLayoutServlet.java:215)
at org.zkoss.zk.ui.http.DHtmlLayoutServlet.doGet(DHtmlLayoutServlet.java:136)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)